Questions and Answers- StraighterLine
Exam Content
Nervous System
Muscle Physiology
Sensory Pathways
Homeostasis
Cellular Physiology
Q1. Action Potential
A nurse explains depolarization. Which ion primarily enters the neuron during this
phase?
A. Potassium
B. Sodium
C. Calcium
D. Chloride
Rationale: Sodium influx causes depolarization.
Q2. Muscle Contraction
Which protein blocks myosin-binding sites on actin?
A. Troponin
B. Tropomyosin
C. Myosin
D. Titin
Rationale: Tropomyosin covers binding sites until calcium binds troponin.
Q3. Synaptic Transmission
Which neurotransmitter is released at the neuromuscular junction?
A. Dopamine
B. Acetylcholine
C. Serotonin
D. GABA
Rationale: Acetylcholine triggers muscle contraction.
Q4. Homeostasis
Which is an example of positive feedback?
A. Blood pressure regulation
B. Childbirth contractions
C. Thermoregulation
D. Blood glucose control
Rationale: Oxytocin amplifies uterine contractions.
,Q5. Sensory Pathways
Which receptor detects light?
A. Rods and cones
B. Hair cells
C. Pacinian corpuscles
D. Olfactory neurons
Rationale: Rods and cones are photoreceptors.
Q6. Muscle Types
Which muscle type is involuntary and non-striated?
A. Skeletal
B. Cardiac
C. Smooth
D. None
Rationale: Smooth muscle controls involuntary movements.
Q7. Membrane Transport
Which process requires ATP?
A. Diffusion
B. Osmosis
C. Active transport
D. Facilitated diffusion
Rationale: Active transport moves ions against gradients.
Q. Nervous System
Which glial cell forms myelin in the CNS?
A. Schwann cells
B. Oligodendrocytes
C. Astrocytes
D. Microglia
Rationale: Oligodendrocytes myelinate CNS axons.
Q9. Reflex Arcs
Which neuron carries impulses to effectors?
A. Sensory neuron
B. Interneuron
C. Motor neuron
D. Relay neuron
Rationale: Motor neurons transmit signals to muscles/glands.
Q10. Endocrine Integration
Which gland regulates metabolism via T3/T4?
A. Pituitary
B. Thyroid
C. Adrenal
, D. Pancreas
Rationale: Thyroid hormones control metabolic rate.
Q11. Cardiac Physiology
Which heart valve prevents backflow into the left atrium?
A. Pulmonary valve
B. Aortic valve
C. Mitral valve
D. Tricuspid valve
Rationale: The mitral (bicuspid) valve separates the left atrium and ventricle.
Q12. Respiratory Mechanics
During inspiration, which muscle contracts to increase thoracic volume?
A. Diaphragm
B. Rectus abdominis
C. Internal intercostals
D. Sternocleidomastoid
Rationale: The diaphragm contracts downward, expanding the thoracic cavity.
Q13. Renal Function
Which structure is the site of filtration in the nephron?
A. Loop of Henle
B. Glomerulus
C. Distal tubule
D. Collecting duct
Rationale: The glomerulus filters blood plasma into the nephron.
Q14. Blood Components
Which blood cells are primarily responsible for immunity?
A. Platelets
B. Erythrocytes
C. Leukocytes
D. Plasma cells
Rationale: Leukocytes (WBCs) defend against pathogens.
Q15. Electrolyte Balance
Which electrolyte is most critical for cardiac action potentials?
A. Sodium
B. Potassium
C. Calcium
D. Chloride
Rationale: Potassium imbalances can cause arrhythmias.
Q16. Respiratory Gas Transport
Most oxygen in blood is carried by:
A. Plasma